Using the info from Specialized I have installed a 170mm drop which allows me to slam the seat all the way and so far not hit the seat on bottoming out
Found this thread when trying to find the info before buying my SL, so wanted to add my data.
Got a 22 medium SL, which according to the above table can have a max insertion of 216mm (which would have limited me to 160mm drop).
However, using a shim to 31.6 I found I can get the full 180mm drop on a One-up V2 180. There may only be around 216mm if you use a 34.9mm post (though I suspect there is more) but with a 31.6mm shimmed I could get 240mm of One-up in there. The bottom 15mm of the one up is the actuator on the bottom, which I suspect is tucking in between the guide tubes..
End result is 27mm of post between the top of the seat clamp and the seal-collar of the post and 180mm of drop. With suspension fully compressed I still have about 5-10mm of clearance between the seat and the tyre (with the seat fully forwards).